New ceilings looking a mess! advice please?

[sparklymarkly]

We have had an extension built which was completed (apart from decorating) at the beginning of February this year. Not long after the builders left, a couple of bits of plaster fell out of a ceiling, revealing clout mails underneath. I filled them & repainted, but now every ceiling has loads of these marks appearing where the plaster is coming away from where the clouts are underneath. I realise that the final finish is a skim coat, but my ceilings really are a very thin coat of plaster! Also, in a couple of places, the ceilings appear to be cracking away from the walls. It doesn't look as if any joint tape has been used between the walls (dry-lined) and ceilings. I suspect that this is down to poor workmanship (we have several other issues regarding this), but I am looking for a bit of advice before I confront the builder about it. Thanks.

 

[^woody^]

If the nails are likely to keep popping, then it may well be better to screw the boards to the joists and pull out any protuding nails, or fit some scrim accross the line of the nails and reskim.

There should be scrim reinforcement at the ceiling/wall junction, and it should not crack. This can be remedied with some flexible caulk.

But there may be an underlying problem with shrinkage and drying out, which may mean further cracking of joints etc. Were the timbers kept dry prior to building in and/or was the work done quite quickly - if so more cracks from drying out may occur

 

[sparklymarkly]

Thanks Woody. I don't think the timbers were ever wet (they were stored inside under cover as far as I remember. Also, the job (plastering) was done fairly quickly, while I was at work, hence I didn't notice the lack of scrim tape (I'm no plasterer, but having worked on sites, I always thought that all joints (and therefore the nails too) should be taped prior to skimming. I think this is where the problem lies, coupled with the ultra-thin plaster coat. The inconvenience of having to have the ceilings re-done now all the decorating is finished and rooms are carpeted really doesn't bear thinking about!!!

 

[chappers]

to add to that boards should be screwed nowadays you can nail but the specs are

Screwed all screws should be twice the thickness of the board and fixed at 230mm centres for 400mm centred joists and 150mm centres for 600mm centred joists

nails shoulsd be galvanised or jagged plasterboard nails and 2.5 times the thickness of the board and fixed at 150mm centres for 400 mm centred joists. I can't find any info for 600mm centred joists.

This has been lifted from several JCT building contracts.

I know these specs are rarely adhered to but my gusee is your nails aren't spaced anywhere near these

 

[sparklymarkly]

Definitely nails - galv clouts (I know 'cos I used some of them to fix some cable channel). And as for spacing, somewhat random by the looks of it!

 

[fitz1]

nails ideally should be uniboded before skimmig.